There emerges from DE 1303705 an eccentric screw pump whose useful life is to be extended. For this purpose, a pump design is provided which comprises a stator housing conical on the inside and a lining conical on the outside. If wear occurs on the lining that leads to an enlargement of the internal cross-section of the lining, the two conical parts, the stator housing and the lining, are shifted towards one another in the longitudinal direction. The lining is placed radially under pressure as a result of this relative movement, no change in the length of the lining of the stator taking place. The position of the lining is brought about by the transfer of compensating discs from the position in front of a flange into a position behind the flange.
DD 279043 A1 shows a stator structure of an eccentric screw pump which, as in DE 1303705, also comprises conically shaped parts, referred to here as sleeve and stator. The reduction in the internal diameter of the stator takes place by the shifting of the parts towards one another. This shifting process is initiated by a tensioning nut, with which a thrust piece shifts the stator into a sleeve.
DE 1553126 discloses in FIG. 4 the design of a rotor, which is made up of an internal and external polygonal sleeve and a polygonal lining.
A rotor designed screw-shaped on the outside can be found in DE 19821065. The stator sleeve and the lining are joined binder-free.
A longitudinally split stator sleeve is shown in FIG. 4 of DE 10042335. Two levers are shown as a closure, said levers entering with the second half of the sleeve element into a keyed connection.
In several examples of embodiment, DE 1 204 072 A1 shows the stator of an eccentric screw pump with the adjacent device parts of a storage container and an outlet pipe. The multi-part cylindrical stator housing is connected via screw connections to this storage container and to the outlet pipe. The distance between the storage container and also between the outlet pipe can be changed by various measures. This distance is changed either directly in the region of the storage container and the outlet pipe or in the central region between the two stator sleeve parts. As a result of the axial change in the distance between the storage container and the outlet pipe, an annular cap reduces the axial length of the stator lining from one or from both sides of the stator. Since, in all the examples of embodiment, the stator lining is clamped in the middle of its longitudinal extension between individual stator parts, a uniform distribution of the material of the stator lining does not take place in the region of the internal cross-section. Moreover, it emerges from all the examples of embodiment that each change in the length of the stator lining is accompanied by a change in the overall length of the pump.
The problem according to the invention consists in making it possible to adapt the pump to the most varied operating conditions without changing the pump length and only with a small assembly outlay.